In metal casting, and in the steel-making process in particular, where molten metal is introduced into a ladle, it is desirable to reduce or eliminate any substances which might cause imperfections in the finished product. In steel making, molten steel may typically contain substances in solution which are known as "reductants" in that they can cause substances such as iron or manganese oxides to reduce to oxides of the reductants. For example, the presence of the reductants aluminum metal, calcium metal or calcium carbide in steel melt will reduce iron and manganese oxides to oxides of aluminum and calcium and calcium aluminates. Aluminum oxide, calcium oxide and calcium aluminate can cause imperfections in finished steel and for this reason their presence is undesirable in the processed steel.
Metal processing ladles (such as metal-casting or metal-forming ladles) commonly employ a spout-filling composition to protect the nozzles of the ladles and assure free opening of the ladle nozzle to remove molten metal. Spout-filling compositions are commonly used for these reasons in steel-making. Chromite sand is a commonly-used constituent of spout-filling compositions used in steel-making ladles. Chromite sand typically contains imperfections. A commonly-occurring imperfection in chromite sand is iron oxide. Interaction between iron oxide in the chromite sand of the spout-filling material and any of the aluminum metal, calcium metal or calcium carbide reductants in solution in the melt is undesirable for the reasons stated above. Thus, it can be appreciated that it would be desirable to have a spout-filling composition which does not contain reducible oxides.